Shock absorbing mechanism



NOV. 8, 1932. l R; H CHURCl-"LL 1,887,287

SHOCK ABSORBING MEGHANI SM Filed sept. so. 1929 2 sheets-sheet 1 Zwdezzazoz l Nov. 8, 1932. R. H. CHURCHILL 1,387,287

SHOCK ABSORBING MECHANISM Filed Sept. 50, 1929 2 Sheets-Sheet 2 Patented Nov. 8; 1932 UNi'rED esra'riisnanriirz. onnnciiinn OF CHICAGO, ILLNOIS y SHOCK BERING MECHANISM Application friet september so, 192e. serial No. 886,025.

pot or snubbing crevice in the linkage in a manner herein shown and described and indicated by the claims.V i@ In the drawings Figure l isa diagrammatic verticalsectionr of a vehicle frame and running gear showing the application of my invention thereto.

Figure 2 is an enlarged verticalsecton of the dashpot device.V

Figure 3 is a diagrammatic plan view' of a modification.

Figure lis a diagrammatic vertical section ofV the vehicle frame and running gear showing a modified form of my invention applied thereto.

Figure 5 is a vertical sectional view of the two-way shock absorber shown in Figure e.

Figure 6 is a diagrammatic vertical sec-V tion similar to Figure l, illust-rating the application ot the snubber type shock absorber as an element of my invention.

ln Figure l the vehicle frame is represented at A with a front axle B and rear axle C.

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One of the front wheels is shown atl) and one rear wheel at The front axle' is attached to the frame and supports it through the medium of a semielliptical spring F of conventional design, and similarly therear axle is connected to the frame by a spring G. The conventional shock absorbing device usually permits the spring, such as the front' spring F, to be compressed as the wheelV D encounters a bump in the road, but to avoid the recoil shock to the vehicle frame which would result if the -spring were allowed to return Vfreely from its compressedrpostion and thus vibrate past its normal position,

the shock absorbing mechanism acts. as a damper to retard Athe return movement so that the spring shall merely regain its normal initial form.V Iktthis is accomplished'rather quickly, the vehicle frame and the load which it carries is sustained by its own inertia of movement in the direction of travel so that 55 it scarcely deviates from a horizontal plane.` j. But inV actual practice there isalways some movement .of the vehicle frame up anddown in response to the encounter of any irregularity by the wheel. This vertical movement first affects the front end of the vehicle and then a moment later similarly affects the rearend of the vehicle, resulting ina longitudinal rocking of the vehicle frame and' bodyvwhich might be described as a,gallop 65 ing motion, and such action is more noticeable in vehicles of relatively short wheelbase because they experience a greater change of angle for a given deviation in the road sur.

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The purpose of this invention is to control and so far as possible eliminate this galloping motion. The drawings illustrate a Vshock absorber of simple, conventional construction 4comprising a cylinder V1 containinga piston'1 75 2 which is normally urged toward one end of the cylinder by a coil spring 3. The cylinder contains a quantity of oil, indicatedl at 4,' which must pass through a port 5in the piston to permit Vmovement of the latter. The passage of the oil yis freely. permitted inV one direction by acheck valve controlling?-V the port 5, but when the piston moves in the opposite direction, the valve closes and the passage of oilis permitted only throughthe` restricted port 7 in the check valve.

As shown, the piston rod 8 is connected by aflexible link 9 to the front axle, and since the cylinder l is shown mounted in horizontal position on the vehicle frame, the connecter 9 passes overV a pulley 10 and thence downward to theiaxle B. It the front wheels'strike` a rise or obstruction f in the road, 'thefront spring F is compressed, thus slackening the flexible connecter 9 and permitting the piston to move toward the rear end of 4the cylinder l l under the stress ofthe spring 3. Then asA the wheels pass the bump in the road and the axle B tends to lmove downwardly away from the frame A, the corresponding recoil movement of the spring F is checked by the restricted flow of oil through the piston 2.

If the cylinder 1 were xedly mounted on the frame, the arrangement would be substantially that of the conventional shock absorbing device as applied to the front axle; but as indicated in Figure 1, the cylinder '1 is slidably carried in a guide tube or sleeve 11, which itself is fixedly secured to the frame A permitting longitudinal movement of the shock absorber cylinder bodily on the frame. The cylinder 1 is provided with an eye 12 at its closed end opposite-theend through which the piston rod 8 extends, and a flexible connecter 13 extends from the eye 12 to the rear axle Gr passing over a pulley 14 similar to the pulley 10 at the forward end. 'lilith this arrangement the recoil force of the front spring v` F as ittends to return from compressed position to its normal form, being unable to move the piston 2 rapidly enough in the cylinder 1, pullsv the cylinder bodily forward in the guide tube 11 and through the flexible connecter-13 pulls up on the lrear axle C, thus compressing the rear spring G. it this instant, (assuming that the vehicle wheels have not actually left the road surface in negotiating theY bump which caused compression of the front springs), the forward end of the frame is star-ting downward as the wheels pass over the bump and before the'front springs have had time to return to normal. This causes av downward dip of the front end of the vehicle, butwith my linkage, just described, the rear end of the vehicle frame is drawn downwardly by the'partial recoil of the front springs,vso that both front andrear ends of the frame are moving downward at the same time, thus greatly lessening i the change of angle which would otherwise result from the downward dipping of the front end.

In other words,-the frame and body of the L vehicle tend to remain levelas a result of the compensating action of the linkage, although the frame may rise and fall in response to irregularities of the road. This mere vertical movement is much less tiring to the occupants of the vehicle than the galloping action which results in a constant change of angle of the backs of the seats as well as thev seats themselves, thus tending to throw the occupants forward in their seats with each road shock experienced by the wheels.

It will be evident that as the restricted leakage of oil through the port 7 continues, the tension on the flexible connecters 19 and 13 will move the piston 2 back to its normal position in the cylinder 1 andthe total linkage extending from one axle to the other will thus be elongated to permit both axles to reencountered by the front wheels, and as the rear wheels ride over this same bump, the action of my shock absorbing linkage will be repeated. rlhe slackening of the flexible connecter 13 will permit the piston 2 to move toward the closed end of the cylinder 1 under stress of its spring 3, thus shortening the complete linkage between the two axles, and then the recoil of the rear spring G will operate through the linkage to pull up on the frontcaxle, resulting in a lowering of the Vfront end of the frame to correspond with the lowering of the rear and as the rear wheels ride down over the pump onto the more level road surface.

If the rear wheels should encounter the obstruction before the springs have fully recovered, Vthe same action will take place, but at a slightly different point in the range of the springs, and in the range of the dashpot cylinder device, but in any event, the tendency will be to hold rthe frame as nearly level as possible'as it rides over the irregularity in the road. y I

Upon encountering a depression in the road surface, unless the vehicle is driven so rapidlythat the wheels practically jump across the depression, there is a tendency for them to follow down in contact with the road surface. If this permits the front springs to expand, there will be a tendency to move the piston 2forward in its cylinder, but since in this direction only the restricted flow of oil can take place through the port 7, the tension on the piston rod 8 -will be transmitted through the dashpet cylinder to the connecting link 13, tending to draw up on the rear axleand thus having the effect of lowering the rear endv of the frame as the front end settles back onto the expanded front springs. That is, if the vehicle body has time to' move downward in response to the depression in the road, it will tend to move downward substantially parallel to itself without the galloping or rocking action which would result if the front and rear axles were not interconnected in accordance with my invention.

Obviously, the encounter of the front wheels with the opposite side of a depression is similar to an encounter with a bump or obstacle in the road surface, and will react on the springs and shock absorbing system in the manner already described.

' Since obstacles or depressions in the road frequently affect only one wheel of a pair, it will be evident that if the linkage shown in Figure 1 were simply duplicated at each side of the vehicle, the up or down move-l ment of the left front wheel would result in corresponding movement of the left rear end' of the frame without so much effecting the right-hand portion of the frame, and this might result in a lateral rocking movement of the body as a whole which would be `un- Cil pleasant. Therefore, it may be desirable to extend the two linkages diagonally with rev spect to the vehicle so that the right-hand portion of the front axle is connected` to the left-hand portion `of the rear axle through a dashpot device or the like, suoli as the: cylinder l; andV similarly the left-hand party of the front axle is linked to the right-hand portion of therear axle. Int-his manner the one-sided road shocks will be compensated by the diagonal transmission of their effects through "the frame, and, of course, where both front and rear wheels encounter an irregularity together, the reaction will aect both ends of the rear axle simultaneously.

This diagonal arrangement is illustrated diagramniatically in Figure 3.

Thus it will be seen that I have provided a stabilizing system for spring supported vehicles .in which the reaction at one end of the vehicle is transmitted to the other end in a manner` tending to avoid undue dis turbance of the body; and incidentally, a single shock absorbing device ismade to serve where heretofore two separate devices have been provided.

The structure shown in Figures 4 and 5 is included t-o indicate the possibility of using a so-callec Ctwo-way shock absorber in accordance with the principles of my invention. In this arrangement the shock absorber cylinder, 20, is shown mounted on the frame, 2l, and instead of flexible cables I have provided rigid link connections, 22, 23, 24 and 25, to the front and rear axles operating through bell cranks, 26 and 2'?, instead of over pulleys. This linkage will thus transmit motion in either direction from the axles to the shock absorber, 20. Y

For purposes of illustration the shock absorber itself is of the air dash pot type having within the cylinder, 20, a piston, 30, whose piston rod, 3l, is connected to the link, 22, while the cylinder itself is provided with an attachment lug, 32, to which the link, 23, is pivotally secured. The cylinder, 20, is carried on a base or support, 33, mounted slidably in a guide member, 34, whose undercut guide-way, 35, is indicated in dotted lines in Figure 5.

The cylinder, 20, is thus capable of bodily movement longitudinally of the vehicle while its piston is movable Within .he cylinder subject to the retarding action Y of the air therein. A check valve, 36, in the piston is adapted to seat against the port,

37, but can only partially seal this port because of a bleed groove therein permitting retarded motionv of the piston toward the closed end of the cylinder. Retardedmovement in the other direction is permitted by laa-rtial leakage at the check valve, 38, while the valve, 36, seals the port, 39, of the piston, 30.

A shock absorber of this type does not yield immediately to compression of the vehicle springs at either end of the car, but such compression will be transmitted through the linkage to the axle at the/opposite end. Thusv direction which rocks the bell crank, 27, inV

adirection for spreading apart the frame and its rea-r springs, thus, tending to raise the rear end of the car by an amount corree,

spending to the height of the bump not compensated-'for by compression of the front springs. VInV other words, the linkage 'tends to maintain the car frame in a levelfposition although it may move vertically in response to road irregularities. Any stresses set up in the connecting linkage between the two axles-will be absorbed tosome extent by the retarded response of the piston, 3.0, in its cylinder, 20, andstrains set up in Ithes'prings of the Vvehicle Vwill be graduallyiV relaxed through the shock absorbing actionv of, this mechanism.A That'fis, it will operate as a shock absorber tothe same extent as though it were applied to a single spring of the vehi` cle, but will serve this purpose forboth front and rear springs by virtue of the con-L necting linka-ge.'v l f A 4 Eig-ure Gis added merely tol illustrate 4the possibility of using the rotary snubber type .Of shock absorber in place of the dash pot tyre except that a cylindrical casing of a snubbe'r type shock absorber is shown at`40, mounted on a base block, 41, which is longitudinally slidable in.guides, 42, on the frame of the vehicle. A cable, 43, connects the base block,

41, with the rear axle and a cable, 44, ex-` tends from within the circular casing,"40, to a connection with the front axle. It Will be understoodthattensioning wind up means within the casing, 40 operate to reel in the cable, 4l, whenever tension therein isrelaxed and then to pay it out yieldingly to retard the recoil of the vehicle spring. This corresponds tothe yielding return of the cable, 9, and piston, 2, of the dash pot device of Figures l and 2, and controls the axle and frame movements in substantially ythe same manner.

l. In combination with al vehicle frame and two axles associated therewith, springs by which said axles are connected to the frame and shock absorbing mechanism comprisinga dashpot device movably mounted on the frame and including a casing with a member-movable relative thereto,`together with linkage` connecting'the'casing to one of the axles, and linkage `connecting said movable `memberwith the other axle where-V by the recoil movement of one axle is transmitted through the 4shock absorbing device to the other axle.

The diagramis similar to Figure '13.

2. In combination with a. vehicle frame, two longitudinally spacedl axlesand springs by which they are connected to said frame, together with linkage connecting said axles .under an initial tension adapted to shorten lautomatically when said tension isrelaxed,

said linkage including means for yieldingly resisting its elongation 'with a force greater than said initial tension for retarding said elongationwhen the tension is resumed or increased. Y

3.,.In combination withna vehicle frame with front and rear axles and springs by which the frame is supported on said. axles, linkage connecting said axles ywithV a takeup device in said linkage adapted to shorten it automatically when the tension is relaxed, but arranged to permit the linkage to clon-y gate at a slower rate, said take-up device employing a suciently lirm grip to render the Yshortened linkage effective for compressing the vehicle springs. Y Y Y 4. In combination with a vehicle frame and twoaxles associated therewith, springs by which said axles are connected to the frame and shock absorbing mechnism movably mounted on the frameand including a casing, a member movable relatively thereto and means for retarding `such relative movement in either direction with suiiicient force for compressing one or more of the vehicle springs ;v together with linkage guided on the. frame and connecting the casing to one of the axles and connecting said movable mem-y ber with the other axle, whereby movements of one axle are distributed through said shock absorbing mechanism to the other axle and to the frame. i Y

5. In combination with a vehicle frame, front and rear axles therefor, and springs by which said axles are connected to the frame, a linkage connecting said axles and including a two-way shock absorber serving as a nonpositive element of said linkageadapted to change its own effective length under stress, but to yieldingly resist and delay such change in either direction, whereby said linkage is arranged to employ the recoil of the springs at oneaxle to compress the springs associated with the other axle.

6. In combination with a vehicle frame,

front and rearaxles therefor, and springs by which said axles are connected to the frame, a linkage connecting said axles but operative for transmitting vmotion between them in one direction only, said linkage permitting compression of the springs at either axle without aHecting the other but employing the recoil of the springs at one axle to compressthe springs associated with the other.

'l'. In combination with a vehicle frame,y

front and rear axles therefor and springs by which said axles are connected to the frame,- a linkage connecting said axles including an automatic take-up device whereby compression of a spring at either axle is permitted without affecting the spring or springs at the other axle, but the linkage is shortened during such compression so as to employ the recoil of the compressed spring for compressing the other spring or springs.

8. In combinationv with a vehicle frame, front and rear axles therefor and springs by which said axles are connected to the frame, Y

which motion is transmitted by the linkage so that recoil of the springs atv one axle serves to compress the springs at the other axle while said non-positive connection permits gradual elongation of the linkage as the parts return to their normal positions.

RALPH H. CHURCHILL. 

